MySql provides sample configuration files within its package (called in Windows "my-huge.ini" , "my-innodb-heavy-4G.ini" , "my-large.ini" , etc). They are to be found in the \xampp\mysql folder. Browse them and determine by yourself what suits you (and your system) best.

You can rename the existing my.ini to my_orig.ini and then copy the one that best suits into the bin folder and rename it to my.ini then edit it and copy over the XAMPP specific entries from my_orig.ini file.

Save the file and restart MySQL, clear your browser's temporary files (cache) and check again what brought on the error message.

Remember you always have your original backup my.ini if all goes pear shaped after editing.

I found the problem. I forgot to export my database before desintalling the v1.7.4 and I copied the .frm files to the v1.7.7. Seems like that doesnt work well. I recreated my database and my tables and now everything is working just fine.